Thermogravimetric analysis-mass spectrometry study of steam oxidation resistance of HCM12A steel at 650°C and 700°C

ABSTRACT

Ferritic/martensitic HCM12A steel specimens were subjected to 190 h of oxidation in Ar + 40% H₂O at 650°C and 700°C. Simultaneous measurements of mass spectrometry and thermogravimetric analysis by a mass spectrometer and a thermobalance of symmetrical furnaces were made. Thermogravimetric measurements verified that the mass gain after oxidation at 650°C was 0.07 mg/cm², whereas at 700°C the mass gain corresponded to ∼1.3 times that at 650°C. Mass spectrometry measurements indicated the presence of only a volatile species of low-intensity chromium (order of ppm) at 700°C (i.e. CrO₂(g)) after between 175 and 190 h of oxidation. At reduced oxidation times, no volatile species were observed. We did not observe any gaseous species at 650°C. The morphology, composition, and structure of samples by scanning electron microscopy, backscattered electron detection, X-ray energy-dispersive spectrometry and X-ray diffraction are described.

KEYWORDS:

• Mass spectrometry
• volatile species
• steam oxidation
• ferritic/martensitic steel
• thermogravimetry measurement

Acknowledgments

The authors acknowledge financial support from the CONSOLIDER-INGENIO 2008-SPAIN, project-CSD200800023 and ENE-2008-06755-C02-02. The authors want to express their gratitude to the Universidad Tecnologica de Pereira for the financial support and to Laura Kuhar, Ph.D., from Edanz Group, for editing a draft of this manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).